The present invention is directed to the field of process chemical delivery in the electronics industry and other applications requiring high purity chemical delivery. More specifically, the present invention is directed to apparatus and processes for the cleaning of process chemical delivery lines, containers and associated apparatus, particularly during changeout of process chemical or process chemical containers in such process chemical delivery lines.
Evacuation and gas purge of process chemical lines has been used to remove residual chemicals from delivery lines. Both vacuum draw and inert gas purge are successful in quickly removing high volatility chemicals, but are not effective with low volatility chemicals. Safety is a problem when extracting highly toxic materials.
Use of solvents to remove residual chemicals is not new. Various patents have sought to clean systems using solvents.
U.S. Pat. No. 5,045,117 describes a method and apparatus for cleaning printed wiring assemblies with a solvent and vacuum action.
U.S. Pat. No. 5,115,576 discloses an apparatus and method of cleaning semiconductor wafers using isopropyl alcohol solvent.
Additional patents regarding solvent cleaning include; U.S. Pat. No. 4,357,175, U.S. Pat. No. 4,832,753, U.S. Pat. No. 4,865,061, U.S. Pat. No. 4,871,416, U.S. Pat. No. 5,051,135, U.S. Pat. No. 5,106,404, U.S. Pat. No. 5,108,582, U.S. Pat. No. 5,240,507, U.S. Pat. No. 5,304,253, U.S. Pat. No. 5,339,844, U.S. Pat. No. 5,425,183, U.S. Pat. No. 5,469,876, U.S. Pat. No. 5,509,431, U.S. Pat. No. 5,538,025, U.S. Pat. No. 5,562,883 and Japanese 8-115886.
However, the present invention simplifies the process and apparatus of the prior art and reduces the size and complexity of the solvent purge system and permits the purging of the interior volume of a process line and also permits the solvent purge volume to be minimized, as will be set forth in greater detail below.